Cultured normal human prostatic and bladder epithelial cells will be treated with carcinogens singly and in combination. The treated cells will be studied for changes in culture longevity, response to growth factors, anchorage-independent growth, morphology and karyotype. Selected cell lines will be tested for tumorigenicity in athymic nude mice. DNA preparations from SV40 transformed prostatic epithelial cells will be tested for their ability to induce anchorage-independence and other changes in growth behavior in the normal prostatic epithelial cells.